Targeting Macrophage Reservoirs in the Macaque Model of Pediatric AIDS

描述(由申请人提供)：尽管传统的抗逆转录病毒疗法(ART)长期抑制血浆病毒血症，但消除艾滋病毒感染儿童和成人中持续存在的病毒库是治愈艾滋病毒感染的关键。为了识别并最终消除这些促进病毒反弹的潜伏感染病毒库，首先要特别识别在ART诱导的潜伏期内携带艾滋病毒的细胞和组织部位，这一点很重要。我们的长期目标是抑制或防止病毒储存库宿主细胞的发展，尽管ARIS在感染艾滋病毒的儿童中使用ART。R21/R33建议的目的是验证在SIV感染和ART治疗的儿童猕猴中，CD4+T细胞和巨噬细胞作为储藏细胞的贡献。我们的中心假设是，在感染SIV的新生儿猕猴中，其发病速度比成年猕猴更快，组织巨噬菌体也是感染后的主要病毒(SIV)储存库。我们假设的基本原理是：(I)新生儿猕猴中的siv感染与在感染hiv的儿童中观察到的疾病的快速发展相平行，以及(Ii)在灵长类动物模型中，siv的储存部位可以被更详细地检查。 在比感染艾滋病毒的人更受控制的实验条件下。我们在这项应用的第一阶段(R21)提出了两个目标：目的1.确定SIV感染的儿童猕猴接受有效的抗逆转录病毒治疗后，CD4+T细胞对病毒库的贡献。我们的工作假设是，在体内消耗SIV感染的新生儿猕猴中的CD4+细胞，接受有效的抗逆转录病毒治疗，将直接证明参与SIV储存库的CD4+T细胞(与巨噬细胞)的比例。我们将使用一个成熟的体内模型，通过注射抗CD4耗竭抗体来清除SIV感染猕猴体内的CD4+T细胞，并进行最佳的抗逆转录病毒治疗。目的2.在接受有效抗逆转录病毒治疗的SIV感染的儿童猕猴中，确定单核/巨噬细胞对病毒库的贡献。我们的工作假设是，SIV感染猕猴体内单核/巨噬细胞的耗尽也将证明巨噬细胞(VS CD4+T细胞)对肺中SIV储存库的贡献。我们将在体内使用脂质体包裹的阿伦磷酸钠，暂时耗尽猕猴的单核/巨噬细胞。这些结果将确定在有效的抗逆转录病毒治疗期间，是否CD4+T细胞和组织巨噬细胞，或者单独一组细胞，都发育和成熟为SIV的储存区。在抗逆转录病毒治疗期间，将对组织样本进行详细检查，以测量病毒水平(RNA和DNA)，并确定感染SIV的存储细胞的特定位置和亚组标记。这将为第二阶段(R33)的目标3奠定基础，以证实是否通过停止抗逆转录病毒疗法来消除或大幅减少病毒库。目的3.确定体内CD4+T细胞和/或单核/巨噬细胞的耗尽是否能阻止SIV感染的新生猕猴停止抗逆转录病毒治疗后的病毒反弹。我们的工作假设是，CD4+T细胞和巨噬细胞都对SIV储存库有贡献，在停止ART后消除其中一个或两个细胞群将导致维持低病毒载量或不含病毒载量。如果出现病毒反弹，将有助于证实病毒储存库的剩余或替代位置。这项研究将有助于制定合理的干预策略，以减少或治愈HIV感染儿童的艾滋病。

DESCRIPTION (provided by applicant): Elimination of virus reservoirs that persist in HIV-infected children and adults despite long-term suppression of plasma viremia by traditional antiretroviral therapy (ART) is crucial for curing HIV infection. To identify and ultimately destro these latently infected virus reservoirs that promote virus rebound, it becomes important to first specifically identify the cells and tissue sites that harbor HIV during latency induced by ART. Our long-term goal is to inhibit or prevent the development of viral reservoir host cells that aris despite ART in HIV-infected children. The purpose of this R21/R33 proposal is to verify the contributions of CD4+ T cells and macrophages as reservoir cells in SIV-infected and ART-treated pediatric macaques. Our central hypothesis is that in SIV-infected newborn macaques where pathogenesis occurs more rapidly than in adults, tissue macro- phages also serve as major virus (SIV) reservoirs after infection. The rationale for our hypothesis is that (i) SIV infections in newborn macaques parallel the rapid disease progression observed in HIV-infected children, and (ii) in the primate model, the reservoir sites of SIV can be examined in finer detail and under more controlled experimental conditions than in HIV-infected humans. We propose two aims in phase I (R21) of this application: Aim 1. To determine the contribution of CD4+ T cells to the virus reservoir in SIV-infected pediatric macaques undergoing effective ART. Our working hypothesis is that in vivo depletion of CD4+ cells in SIV- infected newborn macaques undergoing effective ART will directly demonstrate the proportion of CD4+ T cells (vs macrophages) that contribute to the SIV reservoir. We will use a well-established in vivo model via injection of anti-CD4 depleting antibody to remove CD4+ T cells in the SIV-infected macaques undergoing optimal ART. Aim 2. To determine the contribution of monocytes/macrophages to the virus reservoir in SIV-infected pediatric macaques undergoing effective ART. Our working hypothesis is that the in vivo depletion of monocyte/macrophages of the SIV-infected macaques undergoing effective ART will also demonstrate a contribution of macrophages (vs CD4+ T cells) to the SIV reservoir in the lung. We will use in vivo administration of liposome-encapsulated alendronate that temporarily depletes monocytes/macrophages in macaques. These results will ascertain if both CD4+ T cells and tissue macrophages, or either set of cells alone, develop and mature into reservoirs sites of SIV during effective ART. Tissue specimens will be examined in fine detail to measure viral levels (RNA and DNA) as well as identify specific sites and subset markers of reservoir cells infected with SIV during ART. This will set the foundation for aim 3 of phase II (R33) to corroborate if viral reservoirs were eliminated or drastically reduced by discontinuation of ART. Aim 3. To determine if in vivo depletion of CD4+ T cells and/or monocyte/macrophages prevents virus rebound after discontinuation of ART in SIV-infected newborn macaques. Our working hypothesis is that both CD4+ T cells and macrophages contribute to SIV reservoirs and that elimination of either or both cell populations followed by discontinuation of ART will lead to maintenance of low or absent viral loads. If virus rebound occurs, it will help to corroborate the remaining or alternate sites of the virus reservoirs. This study will contribute to developing rational intervention strategies to reduce or cure AIDS in HIV-infected children.